Description
3331 Temperature Converter, Loop powered, Isolated
Application
- The 3331 temperature converter measures a standard Pt100, TC J and K temperature sensor, and provides an isolated passive analog current output signal.
- High 2 port isolation provides surge suppression and protects the control system from transients and noise.
- The 3331 can be mounted in the safe area or in Zone 2 / Division 2 areas.
- Approved for marine applications.
Technical characteristics
- Flexibly loop powered by 5.5…35 VDC via connectors.
- < 30 ms fast response time with simultaneous sensor error detection when selected.
- Selectable 300 ms response time when signal dampening is needed.
- Selectable internal/external CJC.
- Excellent conversion accuracy in all available ranges, better than 0.05% of span.
- Meeting the NAMUR NE21 recommendations, the 3331 provides top measurement performance in harsh EMC environments.
- The device meets the NAMUR NE43 standard defining out of range and sensor error output values.
- All terminals are protected against overvoltage and polarity error.
- High galvanic isolation of 2.5 kVAC.
- Excellent signal/noise ratio of > 60 dB.
Mounting / installation / programming
- Selectable DIP-settings for easy configuration of more than 1000 factory calibrated measurement ranges.
- The narrow 6.1 mm housing allows up to 163 units to be mounted per meter of DIN rail, without any air gap between units.
- Wide ambient temperature range of -25…+70°C.
Data sheet & Manuals – 3331 Temperature Converter Loop powered Isolated
Data sheet
Manuals
Environmental Conditions
| Operating temperature | -25°C to +70°C |
| Storage temperature | -40°C to +85°C |
| Calibration temperature | 20…28°C |
| Relative humidity | < 95% RH (non-cond.) |
| Protection degree | IP20 |
| Installation in | Pollution degree 2 & meas. / overvoltage cat. II |
Mechanical specifications
| Dimensions (HxWxD) | 113 x 6.1 x 115 mm |
| Weight approx. | 70 g |
| DIN rail type | DIN EN 60715/35 mm |
| Wire size | 0.13…2.5 mm2 / AWG 26…12 stranded wire |
| Screw terminal torque | 0.5 Nm |
| Vibration | IEC 60068-2-6 |
| 2…25 Hz | ±1.6 mm |
| 25…100 Hz | ±4 g |
Common specifications
Supply | |
| Supply voltage | 5.5…35 VDC |
| Max. required power | 0.80 W |
| Internal power dissipation | 19 mW…0.8 W |
Isolation voltage | |
| Isolation voltage, test / working | 2.5 kVAC / 300 VAC (reinforced) |
| Zone 2 / Div. 2 | 250 VAC |
Response time | |
| Response time (0…90%, 100…10%) | < 30 ms / 300 ms (selectable) |
| Voltage drop | 5.5 VDC |
| Signal / noise ratio | Min. 60 dB |
| Programming | DIP-switches |
| Signal dynamics, input | 23 bit |
| Signal dynamics, output | 18 bit |
| EMC immunity influence | < ±0.5% of span |
| Extended EMC immunity: NAMUR NE21, A criterion, burst | < ±1% of span |
| Incorrect DIP-switch setting identification | 3.5 mA |
Input specifications
RTD input | |
| Temperature range, Pt100 | -200…+850°C |
| Min. measurement range (span) | 10°C |
| Accuracy: the greater of | Better than 0.05% of span or 0.1°C |
| Temperature coefficient: the greater of | 0.02°C/°C or ≤ ±0.01%/°C |
| Sensor current | < 150 µA |
| Sensor cable resistance | < 50 Ω per wire |
| Effect of sensor cable resistance (3-/4-wire) | < 0.002 Ω / Ω |
| Sensor error detection | Yes – selectable via DIP-switch |
| Broken sensor detection | > 800 Ω |
| Shorted sensor detection | < 18 Ω |
TC input | |
| Temperature range, TC J | -100…+1200°C |
| Temperature range, TC K | -180…+1372°C |
| Min. measurement range (span) – TC J & K | 50°C |
| Accuracy: the greater of | Better than 0.05% of span or 0.5°C |
| Temperature coefficient: the greater of | 0.1°C/°C or ≤ ±0.01%/°C |
| Sensor cable resistance | < 5 kΩ per wire |
| Cold junction compensation (CJC): Accuracy @ external Pt100 input | Better than ±0.15°C |
| Cold junction compensation (CJC): Accuracy @ internal CJC | Better than ±2.5°C |
| Internal CJC error detection | Yes |
| External CJC error detection | Yes – selectable via DIP-switch |
| Open Thermocouple detection | Yes – selectable via DIP-switch |
Output specifications
Common output specifications | |
| Updating time | 10 ms |
Current output | |
| Programmable signal ranges | 4…20 and 20…4 mA |
| Load (@ current output) | ≤ (Vsupply – 5.5) / 0.023 [Ω] |
| Load stability | ≤ 0.01% of span / 100 Ω |
| Sensor error indication | 3.5 mA or 23 mA / acc. to NAMUR NE43 or OFF |
I.S. / Ex marking
| ATEX | II 3 G Ex ec IIC T4 Gc |
| IECEx | Ex ec IIC T4 Gc |
| FM, US | Cl. I, Div. 2, Gp. A, B, C, D T4 or Cl. I, Zone 2, AEx nA IIC T4 |
| FM, CA | Cl. I, Div. 2, Gp. A, B, C, D T4 or Cl. I, Zone 2, Ex nA IIC T4 |
| EAC Ex | 2Ex nA IIC T4 Gc X |
Observed authority requirements
| EMC | 2014/30/EU & UK SI 2016/1091 |
| LVD | 2014/35/EU & UK SI 2016/1101 |
| ATEX | 2014/34/EU & UK SI 2016/1107 |
| RoHS | 2011/65/EU & UK SI 2012/3032 |
| EAC | TR-CU 020/2011 |
| EAC Ex | TR-CU 012/2011 |
Approvals
| ATEX | KEMA 10ATEX0147 X |
| IECEx | KEM 10.0068X |
| UKEX | DEKRA 21UKEX0055X |
| c FM us | FM17US0004X / FM17CA0003X |
| c UL us, UL 61010-1 | E314307 |
| EAC Ex | EAEU KZ 7500361.01.01.08756 |
| DNV Marine | TAA00001RW |
High-Performance Temperature Signal Conversion with PR Electronics
The 3331 Loop-Powered Isolated Temperature Converter by PR Electronics is an advanced solution for accurate and reliable temperature signal conversion in industrial applications. Designed with galvanic isolation and a loop-powered operation, this converter ensures high accuracy, stability, and seamless integration into process automation systems.
Key Features and Benefits
- Loop-Powered Operation – Reduces wiring complexity and enhances energy efficiency.
- Galvanic Isolation – Protects against ground loops and electrical noise, ensuring superior signal integrity.
- High-Accuracy Temperature Conversion – Supports RTDs, thermocouples, resistance, and voltage inputs.
- Compact & Robust Design – Built for industrial environments with high resistance to electrical interference.
- Easy Configuration – Simple setup and calibration for seamless integration into control systems.
Why Choose PR Electronics?
PR Electronics is a trusted leader in industrial signal conditioning, providing innovative and high-performance temperature converters. The 3331 Loop-Powered Isolated Temperature Converter is designed for optimal performance in process automation, ensuring precision, reliability, and ease of use for demanding industries.
Applications – 3331 Loop powered Isolated Temperature Converter
- Process Automation
- Power Generation
- Food & Beverage Industry
- Chemical & Pharmaceutical Processing
- HVAC & Environmental Monitoring
Get Started Today
Upgrade your temperature signal processing with the PR Electronics 3331 Loop-Powered Isolated Temperature Converter. Contact us today for more information or to discuss a customized solution for your industry needs.




